<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>10</title>
    <style>
      *{
        margin:0;
        padding:0;
      }

      .a{
        background-color:yellow;
        width: 300px;
        height:200px;
        float:left;
      }

      .b{
        background-color:pink;
        height:200px;
        margin:0 200px 0 300px;

      }

      .c{
        background-color:green;
        width: 300px;
        height: 200px;
        float:right; 
      }
     
      .b-1{
        background-color:#fff;
        width: 40px;
        height: 40px;
        display:inline-block;
      }

      
    
    </style>
</head>
<body>
  
    <div class="a"></div>
    <div class="c"></div>
    <div class="b">
        <span class="b-1"></span>
    </div>
    


    

</body>
</html>